Transition-Metal-Free Synthesis of 2-Substituted Benzothiazoles from Nitrobenzenes, Methylheteroaryl Compounds, and Elemental Sulfur, Based on Nitro-Methyl Redox-Neutral Cyclization.

Greener and more sustainable chemical processes are required to address increasing environmental pollution and depletion of natural resources. This paper aims to develop greener and more sustainable modern synthetic chemical processes using redox-neutral cyclization. Redox-neutral cyclization has been shown to promote the efficient synthesis of 2-substituted benzothiazoles from easily available nitrobenzenes, methyl-heteroaryl compounds, and elemental sulfur in the absence of transition-metal catalysts.

Synthesis of Aryl Iodides from Arylhydrazines and Iodine.

A metal- and base-free method is developed for the synthesis of aryl iodides from arylhydrazine hydrochlorides and iodine. A wide variety of aryl iodides can be conveniently synthesized by an equimolar reaction of arylhydrazine hydrochlorides and I in dimethyl sulfoxide at 60 °C for 6 h. In the iodination step, arylhydrazines are oxidized by iodine to form arenediazonium salts, which undergo single-electron transfer from iodide anion to give aryl and iodine radicals; subsequent combination of them affords the corresponding aryl iodides.

Transition-Metal-Free and Oxidant-Free Cross-Coupling of Arylhydrazines with Disulfides: Base-Promoted Synthesis of Unsymmetrical Aryl Sulfides.

A novel synthesis of unsymmetrical aryl sulfides, which requires no transition metal catalyst and no oxidant, was developed. This base-promoted cross-coupling reaction proceeded using arylhydrazines and 1 equiv amount of disulfides under inert gas conditions to afford the unsymmetrical aryl sulfides in good yields.

Controlling the Polarity of Fullerene Derivatives to Optimize Nanomorphology in Blend Films.

Developing a design strategy to establish the compatibility of acceptor materials with donor materials is important for the rational development of organic solar cells. We synthesized 2,6-dimethoxyphenyl methanofullerene derivatives to realize an enhanced open-circuit voltage, and we investigated polarities and their effects on the film morphology of the active layer. The polarities of the synthesized fullerene derivatives were affected significantly by the presence of functional groups, such as methoxy, ether, and ester groups.

Design of fullerene derivatives for stabilizing LUMO energy using donor groups placed in spatial proximity to the C60 cage.

A series of arylated dihydrofullerene derivatives were synthesized to elucidate the effective design of fullerene derivatives for enhancing the performance of organic photovoltaics. The LUMO energy of the fullerenes was estimated by the first reduction potential and theoretical calculations. The results showed that the methoxy groups substituted at spatial proximity to the fullerene core offered significant stabilization of the LUMO level.